You're talking about meals that take 2 prepped ingredients (pork/veggies, pork/ramen, cereal/milk) versus something that takes on the order of 10 (tortilla, rice, beans, some kind of protein, cheese, pico, lettuce, guac, sour cream, hot sauce), many of them individually seasoned. That's exactly where the economies of scale come in!

Point out that prepping meals at home is a great way to save money, sure. It just falls flat when pushed in the context of burritos. I would posit that the majority of people who set out to save money by trying to make burritos at home do end up wasting a significant portion of the ingredients, and end up considering the experiment a failure. So I'd say if you're trying to encourage financial savvy, focusing on burritos actually hurts that goal.